1. Technical Field
The present invention relates generally to display devices for data processing systems and in particular to rear projection display devices. Still more particularly, the present invention relates to rear projection display devices employing curved translucent projection screens.
2. Description of the Related Art
A variety of contemporary devices require or benefit from display systems which occupy the field of vision of a user, either completely or in a substantial portion. In general, display devices designed to occupy the most significant majority of a user's field of vision may be loosely referred to a "full field" display device. Examples of such devices include flight simulators, whether utilized for training or for entertainment, and other environment simulators. Wrap-around or large, collimated display systems occupying the user's field of vision in such devices reduce a user's awareness of the actual surroundings and increase the user's awareness of the simulated environment.
An economical approach to full field display systems employs rear projection to a translucent display screen. One implementation of this approach is depicted in FIG. 5. The display system 502 includes a plurality of flat display screens 504-508 arranged to surround the focal point 510 of a user's field of vision. Each display screen 504-508 has an associated projection device 512-516 projecting a portion of the total image. This arrangement requires complex adaptations for image splitting and edge matching of the individual image portions. The boundaries between the separate image portions cannot be completely concealed from the user, and differences in distance to the image may be perceptible to the user.
An alternative implementation of the rear projection approach to full field display systems is depicted in FIG. 6. Display system 602 employs a curved display screen 604, a bubble which is nearly hemispherical. A single projection device 606 projects the complete image onto the screen 604. However, the projected image as it appears on screen 604 is distorted, which is minimal in a central region 608 and becomes increasingly distorted near outer edges 610 of screen 604. Therefore, complex image warping adaptations are required to offset the image distortion.
It is desirable, therefore, to provide a full field display system which does not require complex image management adaptations. It would further be advantageous if the full field display system employed rear projection to a curved display screen without significant image distortion.